Can there be three 1 inch fish in a 10 gallon tank?

It is generally recommended to have at least 1 gallon of water per inch of fish, so three 1-inch fish should theoretically be able to live comfortably in a 10-gallon tank. However, there are a few factors to consider that could affect the suitability of this setup:

- The species of fish: Different fish have different requirements for space, water quality, and tankmates. Some fish may become stressed or aggressive if they feel cramped or if they do not have compatible tankmates.

- The activity level of the fish: More active fish may need more space to swim and explore.

- The amount of decoration and filtration in the tank: A tank with a lot of plants and other decorations can provide more hiding places and reduce stress for the fish. A good filtration system can help to remove waste and keep the water quality high.

If you are considering keeping three 1-inch fish in a 10-gallon tank, be sure to do some research on the specific species you are interested in and make sure that they are compatible with each other and that the tank provides them with enough space and resources. You may also want to consider adding some plants or other decorations to provide hiding places and reduce stress for the fish.